Inosine mono phosphate (IMP) is a precursor of the two purine nucleotides, adenosine mono phosphate (AMP) and guanosine monophosphate (GMP): IMP -----adenylosuccinate ------AMP and IMP to xanthine monophosphate (XMP)---GMP. The reaction IMP----- adenylosuccinate is catalyzed by the enzyme synthetase which was purified and IMP---XMP is catalyzed by the enzyme IMP dehydrogenase which was purified also .Adenylosuccinate synthetase of rat liver is stimulated...